JP2015028309A - Control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine capable of avoiding generation of a surge during regeneration control of an exhaust emission control device.SOLUTION: When a vehicle is in a deceleration state, ongoing post-processing operation is determined, a suction air amount deviation is less than a prescribed value, a surge noise limit is equal to or less than a prescribed value, and the risk of generation of a surge noise is determined, a surge noise target throttle opening at the suction air amount deviation and the surge noise limit in post-processing operation is calculated based on the suction air amount deviation, the surge noise limit, and a surge noise target throttle opening map, and operation of an electronic control throttle valve (15) is controlled so that an opening of the electronic control throttle valve (15) is to be the surge noise target throttle opening.

Description

  The present invention relates to a control device for an internal combustion engine, and more particularly to a technique for avoiding a compressor surge during regeneration control of an exhaust purification device.

Conventionally, diesel engines are intended to improve output and fuel consumption, and to reduce chemical substances such as particulate matter (PM) mainly composed of carbon monoxide (CO), hydrocarbons (HC) and graphite in exhaust gas. A variable nozzle turbocharger having a nozzle whose opening degree can be changed in the exhaust passage and capable of supercharging from a low speed range of the vehicle is employed.
In a diesel engine employing such a variable nozzle turbocharger, when the vehicle is decelerated, the opening degree of the exhaust gas recirculation valve is set according to the fuel injection amount, and the flow rate of air passing through the compressor of the variable nozzle turbocharger is set. A technique for suppressing the decrease and suppressing the occurrence of surge has been developed (Patent Document 1).

JP 2012-246803 A

  Such a diesel engine of the above-mentioned patent document includes a NOx occlusion reduction catalyst and a diesel particulate filter. The NOx occlusion reduction catalyst is poisoned by the sulfur content in the exhaust gas, and the diesel particulate filter accumulates particulate matter in the exhaust gas, so that the NOx occlusion reduction catalyst is subjected to sulfur desorption treatment and diesel particulates. A filter regeneration process is performed.

In the sulfur desorption process of the NOx storage reduction catalyst and the regeneration process of the diesel particulate filter, it is necessary to introduce high-temperature and rich exhaust gas into the NOx storage reduction catalyst and the diesel particulate filter. The amount of intake air is adjusted by adjusting the opening of a throttle valve disposed downstream in the intake flow direction.
However, if the opening of the throttle valve is decreased to reduce the amount of intake air with the high supercharging pressure remaining, the allowable air flow rate passing through the compressor corresponding to the supercharging pressure will be below the minimum allowable value. A surge in which intake air intermittently flows backward from upstream to downstream is generated. The occurrence of surge is not preferable because it causes abnormal noise and eventually breaks the compressor blades.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a control device for an internal combustion engine capable of avoiding a surge during regeneration control of the exhaust purification device. It is in.

  In order to achieve the above object, in the control apparatus for an internal combustion engine according to claim 1, the supercharging ratio is provided in an exhaust passage of the internal combustion engine mounted on the vehicle so as to vary the supercharging ratio by varying the exhaust passage area. Flow variable variable supercharging means including a turbine having variable means, a compressor disposed in an intake passage of the internal combustion engine and driven by the turbine, and an actual intake air amount for detecting an actual intake air amount Detecting means; target intake air amount setting means for setting a target intake air amount based on an operating state of the internal combustion engine; and intake air amount adjusting means arranged in the intake passage for adjusting the actual intake air amount; The exhaust gas purification means downstream of the exhaust passage flow variable supercharging means, and a limit supercharging ratio at which surge noise is generated in the compressor is preset according to the intake air amount of the internal combustion engine, Internal combustion A margin calculating means for calculating a margin to the limit supercharging ratio in the operating state of the engine, and a deviation between the actual intake air amount and the target intake air amount during the exhaust purification capacity recovery operation of the exhaust purification means; Intake air amount control means for controlling the opening degree of the intake air amount adjusting means according to the margin.

Further, in the control device for an internal combustion engine according to claim 2, the opening degree of the intake air amount adjusting means according to claim 1 is such that the opening degree of the intake air amount control means increases as the margin decreases. It is characterized by controlling.
According to a third aspect of the present invention, there is provided a control device for an internal combustion engine according to the first or second aspect, wherein the target intake air amount adjusting means is controlled so as to be the target intake air amount set by the target intake air amount setting means. A first target opening degree setting means for setting a degree, and as the actual intake air amount becomes larger than the target intake air amount, the target opening is set to be larger, and the target intake air amount is larger than the actual intake air amount. And a second target opening setting means for setting the target opening to a smaller value as it increases, wherein the intake air amount control means is at least in a state where the vehicle is decelerating and during the exhaust purification capacity recovery operation. In some cases, the opening degree of the intake air amount adjusting means is controlled based on the target opening degree set by the first and second target opening degree setting means.

According to a fourth aspect of the present invention, there is provided a control device for an internal combustion engine according to any one of the first to third aspects, wherein the actual intake air amount and the target intake air amount are determined during the exhaust purification capacity recovery operation of the exhaust purification means. And a supercharging ratio control means for controlling the opening degree of the supercharging ratio variable means according to the deviation and the margin.
According to a fifth aspect of the present invention, there is provided a control device for an internal combustion engine according to the fourth aspect, wherein the supercharging ratio control means is configured to control the supercharging ratio variable means so that the supercharging ratio becomes smaller as the margin becomes smaller. The opening degree is controlled.

According to the first aspect of the present invention, the opening degree of the intake air amount adjusting means is controlled in accordance with the deviation and margin between the actual intake air amount and the target intake air amount during the operation of recovering the exhaust purification ability of the exhaust purification means. For example, during the exhaust purification capacity recovery operation of the exhaust purification means such as the sulfur desorption process of the NOx occlusion reduction catalyst or the regeneration process of the diesel particulate filter, the intake air amount is adjusted so as to increase as the margin decreases. By controlling the opening of the means, the intake air amount can be increased and the occurrence of a surge can be avoided when the intake air amount decreases and there is no allowance for surges. Can be suppressed.
In addition, by controlling the opening of the intake air amount adjusting means so that the deviation between the actual intake air amount and the target intake air amount does not increase, the intake air amount is adjusted to the optimum flow rate for the exhaust purification capacity recovery operation of the exhaust purification means. To suppress a decrease in the temperature of the exhaust gas introduced into the exhaust gas purification means and an increase in oxygen concentration in the exhaust gas, and to prevent a regeneration failure due to a decrease in the temperature of the exhaust gas purification means and an excessive temperature rise of the exhaust gas purification means due to an excessive oxygen supply amount. Can do.

Further, according to the invention of claim 2, the opening degree of the intake air amount adjusting means is controlled so that the opening degree becomes larger as the margin becomes smaller, and during the exhaust purification capacity recovery operation of the exhaust purification means, Since the amount of intake air can be increased, the occurrence of surge can be avoided and the generation of surge noise can be suppressed.
According to the invention of claim 3, when the vehicle is in a decelerating state and the exhaust purification capability recovery operation of the exhaust purification means is in operation, the optimum intake air amount is obtained while suppressing the generation of surge noise. be able to. For this reason, the temperature reduction of the exhaust gas introduced into the exhaust gas purification unit and the increase in the oxygen concentration in the exhaust gas are suppressed, and the regeneration failure due to the temperature decrease of the exhaust gas purification unit and the excessive temperature rise of the exhaust gas purification unit due to the excessive oxygen supply amount are prevented. be able to.

  According to the fourth aspect of the present invention, during the operation of recovering the exhaust purification capacity of the exhaust purification means, the degree of opening of the supercharging ratio variable means is determined according to the deviation and margin between the actual intake air amount and the target intake air amount. For example, during the operation of recovering the exhaust purification capacity of the exhaust purification means such as the sulfur desorption process of the NOx storage reduction catalyst and the regeneration process of the diesel particulate filter, the supercharging ratio decreases as the margin decreases. By controlling the opening degree of the supercharging ratio variable means so that the exhaust pressure upstream of the turbine is reduced and the actual supercharging pressure is reduced, the occurrence of surge can be avoided, Occurrence can be suppressed.

  According to the invention of claim 5, the opening degree of the supercharging ratio variable means is controlled so that the supercharging ratio becomes smaller as the margin becomes smaller during the exhaust purification capacity recovery operation of the exhaust purification means. By reducing the exhaust pressure upstream of the turbine and reducing the actual supercharging pressure, it is possible to avoid the occurrence of a surge and suppress the occurrence of a surge noise.

1 is a schematic configuration diagram of an engine to which a control device for an internal combustion engine according to the present invention is applied. It is a schematic block diagram of the electronic control unit to which the control apparatus of the internal combustion engine which concerns on this invention was applied. It is a control block diagram which shows the structure of the torque calculation block of an electronic control unit. It is a control block diagram which shows the structure of the supercharging control block of an electronic control unit. It is a control block diagram which shows the structure of the throttle valve control block of an electronic control unit. It is a control block diagram which shows the structure of the exhaust gas recirculation valve control block of an electronic control unit. It is a flowchart of variable nozzle turbocharger control performed in an electronic control unit. It is a flowchart of throttle valve control performed by an electronic control unit.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an engine to which a control device for an internal combustion engine is applied. FIG. 2 is a schematic configuration diagram of an electronic control unit to which a control device for an internal combustion engine is applied. FIG. 3 is a control block diagram showing the configuration of the torque calculation block. FIG. 4 is a control block diagram showing the configuration of the supercharging control block. FIG. 5 is a control block diagram showing the configuration of the throttle valve control block. FIG. 6 is a control block diagram showing the configuration of the exhaust gas recirculation valve control block.

As shown in FIG. 1, an engine (internal combustion engine) 1 is a multi-cylinder direct injection internal combustion engine (for example, a common rail diesel engine). Specifically, high pressure fuel accumulated in the common rail is used as fuel for each cylinder. The fuel nozzle is supplied to the injection nozzle 2 and can be injected from the fuel injection nozzle 2 into the combustion chamber 3 of each cylinder at an arbitrary injection timing and injection amount.
Each cylinder of the engine 1 is provided with a piston 4 that can slide up and down. The piston 4 is connected to the crankshaft 6 via a connecting rod 5. A crank angle sensor 7 for detecting the rotational speed and a flywheel (not shown) are provided at one end of the crankshaft 6.

An intake port 8 and an exhaust port 9 are communicated with the combustion chamber 3.
The intake port 8 is provided with an intake valve 10 for communicating and blocking between the combustion chamber 3 and the intake port 8. In addition, the exhaust port 9 is provided with an exhaust valve 11 for performing communication and blocking between the combustion chamber 3 and the exhaust port 9.

  Upstream of the intake port 8 is an air cleaner 12 that removes dust in the fresh air sucked from the most upstream, and a variable nozzle turbocharger 13 that compresses the sucked fresh air by using the energy of the exhaust (flow path variable supercharging means). , A compressor housing (not shown), an intercooler 14 for cooling the compressed and heated fresh air, an electronically controlled throttle valve (intake air amount adjusting means) 15 for adjusting the flow rate of fresh air, so-called intake air amount, and an intake air An intake manifold (intake passage) 16 that distributes the air to each cylinder is provided to communicate with each other via an intake pipe (intake passage) 17. The electronically controlled throttle valve 15 is provided with a throttle position sensor 18 for detecting the degree of opening of the throttle valve.

  Downstream of the air cleaner 12 and upstream of the compressor housing of the variable nozzle turbocharger 13 is an air flow sensor (actual intake air) for detecting the amount of fresh air sucked into the combustion chamber 3, so-called actual intake air amount (mass flow rate). (Quantity detecting means) 19 is provided so as to protrude into the passage. Further, a boost sensor 20 for detecting the pressure of intake air sucked into the combustion chamber 3, that is, a so-called actual supercharging pressure (actual supercharging pressure detecting means), and an intake air temperature sensor 21 for detecting the temperature of the intake air are incorporated. It is provided so as to protrude into the manifold 16.

Downstream of the exhaust port 9, an exhaust manifold (exhaust passage) 22 that collects exhaust exhausted from each cylinder, a turbine housing (not shown) that introduces exhaust into the variable nozzle turbocharger 13, and an exhaust pipe (exhaust passage) 23 Are provided to communicate with each other.
In the turbine housing of the variable nozzle turbocharger 13, variable blades (supercharging ratio varying means) (not shown) that vary the passage area of the exhaust passage are provided. The variable nozzle turbocharger 13 is provided with an actuator (supercharging ratio variable means) 13a that mechanically operates the variable blades.

In the exhaust pipe 23, an oxidation catalyst (exhaust purification means) 24 that oxidizes components to be oxidized in order from upstream, and diesel particulates that collect and burn particulate matter mainly composed of graphite in the exhaust. A filter (exhaust gas purification means) 25 and a NOx occlusion reduction catalyst (exhaust gas purification means) 26 that occlude and reduce NOx in the exhaust gas are provided so as to communicate with each other.
A pipe connected to a differential pressure sensor 25 b for detecting a differential pressure between the upstream and downstream of the diesel particulate filter 25 is inserted into the exhaust pipe 23 upstream and downstream of the diesel particulate filter 25. The amount of PM deposited in the diesel particulate filter is calculated from the differential pressure between the upstream and downstream of the diesel particulate filter 25 detected by the differential pressure sensor 25b.

  A fuel addition valve 27 for adding a reducing agent to the exhaust gas is provided so as to protrude into the exhaust pipe 23 downstream of the variable nozzle turbocharger 13 of the exhaust pipe 23 and upstream of the oxidation catalyst 24. Further, exhaust temperature sensors 28 a, 28 b and 28 c for detecting the temperature of the exhaust protrude into the exhaust pipe 23 at the exhaust pipe 23 upstream and downstream of the oxidation catalyst 24 and the exhaust pipe 23 downstream of the diesel particulate filter 25. It is provided to do. Further, the NOx storage reduction catalyst 26 is provided with an exhaust temperature sensor 28 d that detects the temperature of the exhaust so as to protrude into the NOx storage reduction catalyst 26.

An A / F sensor 29 that detects an oxygen concentration that is an oxygen ratio in the exhaust gas, that is, a so-called O ₂ concentration, is provided downstream of the NOx storage reduction catalyst 26 in the exhaust pipe 23 so as to protrude into the passage.
The intake manifold 16 and the exhaust manifold 22 are provided with an exhaust gas recirculation path 30 for returning a part of the exhaust gas to the intake air so as to communicate with each other. The exhaust gas recirculation path 30 is provided with an exhaust gas recirculation valve 31 that adjusts the amount of exhaust gas returning to the intake air, that is, an exhaust gas recirculation amount, and an exhaust gas recirculation cooler 32 that cools the exhaust gas returned to the intake air.

  The fuel injection nozzle 2, crank angle sensor 7, actuator 13a, electronically controlled throttle valve 15, throttle position sensor 18, air flow sensor 19, boost sensor 20, intake air temperature sensor 21, fuel addition valve 27, exhaust temperature sensor 28, A / F sensor 29, exhaust gas recirculation valve 31, accelerator position sensor 33 for detecting the degree of operation of an accelerator pedal operated by a driver of a vehicle on which the engine 1 is mounted, an atmospheric pressure sensor 34 for detecting atmospheric pressure, and an outside air temperature are detected. Various devices such as the outside air temperature sensor 35 and various sensors are control devices for performing overall control of the engine 1, and are input / output devices, storage devices (ROM, RAM, nonvolatile RAM, etc.), timers, Electronic control unit that includes a central processing unit (CPU), etc. Means, intake air amount control means, supercharging ratio control means, target boost pressure setting means, target intake air amount setting means, first target opening setting means, second target opening setting means) 40 The electronic control unit 40 controls the operation of various devices based on information from various sensors.

  On the input side of the electronic control unit 40, a crank angle sensor 7, a throttle position sensor 18, an air flow sensor 19, a boost sensor 20, an intake air temperature sensor 21, an exhaust air temperature sensor 28, an A / F sensor 29, an accelerator position sensor 33, a large Sensors such as an atmospheric pressure sensor 34 and an outside air temperature sensor 35 are electrically connected, and detection information from these various devices and various sensors is input.

On the other hand, the fuel injection nozzle 2, the actuator 13 a, the electronic control throttle valve 15, the fuel addition valve 27, and the exhaust gas recirculation valve 31 are electrically connected to the output side of the electronic control unit 40.
Thus, the electronic control unit 40, based on the detection value of each sensor, the fuel injection amount and injection timing from the fuel injection nozzle 2, the opening degree of the variable blade of the variable nozzle turbocharger 13, the so-called variable blade opening degree, electronic control The throttle valve opening of the throttle valve 15, the so-called throttle opening, the amount of reducing agent added from the fuel addition valve 27, and the opening of the exhaust gas recirculation valve 31 are optimally controlled. Further, the electronic control unit 40 detects the generation of sulfur poisoning due to the sulfur content contained in the fuel in the NOx storage reduction catalyst 26 and the accumulation of graphite in the diesel particulate filter 25 based on the detection value of each sensor. And post-treatment operation (equivalent to the exhaust purification ability recovery operation of the present invention) such as S purge treatment for eliminating sulfur poisoning of the NOx storage reduction catalyst 26 and regeneration treatment for burning graphite deposited on the diesel particulate filter 25 Thus, the operation of the fuel injection nozzle 2, the variable nozzle turbocharger 13, the electronic control throttle valve 15, the fuel addition valve 27, and the exhaust gas recirculation valve 31 is controlled.

As shown in FIG. 2, the electronic control unit 40 includes a torque calculation block 41, a supercharging control block 42, a throttle valve control block 43, and an exhaust recirculation valve control block 44.
As shown in FIG. 3, the torque calculation block 41 includes a target torque calculation unit 41a, a target torque change rate calculation unit 41b, a driver intention determination unit 41c, and a fuel injection amount calculation unit 41d.

  The target torque calculation unit 41a stores a target torque map for calculating a target torque (corresponding to the load of the present invention) from the accelerator opening and the engine speed. Then, the target torque calculation unit 41a, based on the accelerator opening detected by the accelerator position sensor 33, the engine rotational speed detected by the crank angle sensor 7, and the target torque map, Calculate the target torque at the rotational speed. Then, the calculation result is supplied to the target torque change rate calculation unit 41 b, the supercharging control block 42, the throttle valve control block 43, and the exhaust gas recirculation valve control block 44.

The target torque change rate calculation unit 41b calculates a target torque change rate, which is a change rate of the target torque per time, based on the target torque calculated by the target torque calculation unit 41a. Then, the calculation result is supplied to the driver intention determination unit 41c.
If the target torque change rate calculated by the target torque change rate calculation unit 41b is greater than the first predetermined value, the driver intention determination unit 41c determines that the driver is requesting acceleration. If the target torque change rate is smaller than a second predetermined value set to a value smaller than the first predetermined value, it is determined that the driver is requesting deceleration. The first predetermined value and the second predetermined value may be the same numerical value. Then, the determination result is supplied as an intention determination result to the supercharging control block 42, the throttle valve control block 43, and the exhaust gas recirculation valve control block 44.

  The fuel injection amount calculation unit 41d stores a fuel injection amount map for calculating the fuel injection amount from the target torque and the engine speed. The fuel injection amount calculation unit 41d then calculates the target torque based on the target torque calculated by the target torque calculation unit 41a, the engine rotation speed detected by the crank angle sensor 7, and the fuel injection amount map. A fuel injection amount at the engine speed is calculated. Then, the calculation result is supplied to the target exhaust gas recirculation valve opening calculation unit 44c, the exhaust gas recirculation amount calculation unit 44d, and the target throttle opening calculation unit 43b.

As shown in FIG. 4, the supercharging control block 42 includes a target supercharging pressure calculation unit 42a, a target variable blade opening degree calculation unit 42b, an intake air amount conversion unit 42c, a surge noise limit calculation unit 42d, The turbocharger deviation calculation unit 42e, the surge abnormal noise target variable blade opening calculation unit 42f, the surge abnormal noise occurrence determination unit 42g, and the variable blade opening control unit 42h are configured.
The target boost pressure calculation unit 42a stores a target boost pressure map for calculating the target boost pressure based on the target torque and the engine speed. Then, the target boost pressure calculation unit 42a is based on the target torque calculated by the target torque calculation unit 41a, the engine rotation speed detected by the crank angle sensor 7, and the target boost pressure map. The target boost pressure at the torque and the engine speed is calculated. And the said calculation result is supplied to the supercharging deviation calculation part 42e.

  The target variable blade opening calculation unit 42b includes a target variable blade opening that is a target opening of the variable blade of the variable nozzle turbocharger 13 based on the target torque and the engine speed during normal operation of the engine 1 (supercharging ratio of the present invention). A target variable blade opening map for calculating the basic opening of the variable means) and the target opening of the variable blade of the variable nozzle turbocharger 13 based on the target torque and the engine speed during the post-processing operation of the engine 1. A target variable blade opening degree map for post-processing operation for calculating the target variable blade opening degree (corresponding to the basic opening degree of the supercharging ratio variable means of the present invention) is stored. The target variable blade opening degree calculation unit 42b is detected by the target torque and crank angle sensor 7 calculated by the target torque calculation unit 41a when the engine 1 is in normal operation based on the post-processing operation information. Based on the engine rotation speed and the target variable blade opening map, the target torque during normal operation and the target variable blade opening at the engine rotation speed are calculated. Further, when the engine 1 is in the post-processing operation based on the post-processing operation information, the target variable blade opening degree calculation unit 42b is based on the target torque, the engine rotation speed, and the target variable blade opening map at the time of the post-processing operation. Then, the target variable blade opening degree at the target torque and the engine speed at the time of the post-processing operation is calculated. In addition, even if the engine 1 is in normal operation, if the operating state of the engine 1 satisfies a predetermined condition, the target variable blade opening degree is set based on the supercharging deviation calculated by the supercharging deviation calculating unit 42e. Performs boost pressure feedback control to be calculated. Then, the calculation result is supplied to the variable blade opening degree control unit 42h.

The intake air amount conversion unit 42c calculates the actual intake air amount (mass flow rate) detected by the air flow sensor 19 and the intake air temperature detected by the intake air temperature sensor 21 and the atmospheric pressure detected by the atmospheric pressure sensor 34. The actual intake air amount (volume flow rate) is converted with the outside air temperature detected by the outside air temperature sensor 35. Then, the conversion result is supplied to the surge abnormal noise limit calculation unit 42d.
The surge abnormal noise limit calculation unit 42d has a limit supercharging ratio map for calculating a limit supercharging ratio that is a limit supercharging ratio at which abnormal noise due to surge occurs based on the actual intake air amount (volume flow rate). Is remembered. The surge noise limit calculation unit 42d is a ratio between the actual supercharging pressure and the atmospheric pressure based on the actual supercharging pressure detected by the boost sensor 20 and the atmospheric pressure detected by the atmospheric pressure sensor 34. Calculate the actual supercharging ratio. Further, the surge abnormal noise limit calculation unit 42d determines the actual intake air amount (volume flow rate) based on the actual intake air amount (volume flow rate) converted by the intake air amount conversion unit 42c and the limit supercharging ratio map. A limit supercharging ratio (corresponding to the limit supercharging ratio in the operating state of the internal combustion engine of the present invention) is calculated. Then, the surge abnormal noise limit calculation unit 42d has a margin until the occurrence of surge abnormal noise based on the intention determination result supplied from the driver intention determination unit 41c and the calculated limit supercharging ratio and actual supercharging ratio. The surge noise limit (corresponding to the margin of the present invention) is calculated. The surge abnormal noise limit indicates the margin to the occurrence of abnormal noise due to surge, and even if it is calculated by subtracting the actual supercharging ratio from the limiting supercharging ratio, Either may be calculated by dividing the supply ratio. Note that the surge noise limit indicates that the smaller the numerical value, the less room is left for the occurrence of surge noise. Then, the calculation result is supplied to the surge variable target variable blade opening degree calculation unit 42f, the throttle valve control block 43, and the exhaust gas recirculation valve control block 44.

The supercharging deviation calculating unit 42e subtracts the target supercharging pressure calculated by the target supercharging pressure calculating unit 42a and the actual supercharging pressure detected by the boost sensor 20 to obtain a supercharging deviation (actual supercharging pressure). And equivalent to the target boost pressure). Then, the calculation result is supplied to the exhaust gas recirculation valve control block 44.
The target variable blade opening calculation unit 42f for surge abnormal noise includes the target opening of the variable blade of the variable nozzle turbocharger 13 that avoids abnormal noise due to a surge due to the supercharging deviation and the surge abnormal limit during normal operation of the engine 1. Surge noise target variable blade opening map for calculating a certain surge noise target variable blade opening, and avoiding noise due to surge from the intake air amount deviation and surge noise limit during post-processing operation of engine 1 The target variable blade opening map for surge abnormal noise during post-processing operation for calculating the target variable blade opening for surge abnormal noise that is the target opening of the variable blade of the variable nozzle turbocharger 13 is stored. In addition, the target variable blade opening map for surge abnormal noise and the target variable blade opening map for surge abnormal noise during post-processing operation have a large target variable blade opening for surge abnormal noise as the surge abnormal noise limit decreases. That is, the supercharging ratio is set to be small. Further, the target variable blade opening map for surge abnormal noise during post-processing operation shows that as the intake air amount deviation described later (corresponding to the deviation between the actual intake air amount and the target intake air amount of the present invention) decreases, The target variable blade opening for sound is set to be large. Then, the surge variable target variable blade opening degree calculation unit 42f, when the engine 1 is in normal operation based on the post-processing operation information, the supercharging deviation calculated by the supercharging deviation calculation unit 42e, and the surge abnormality Based on the surge noise limit calculated by the sound limit calculation unit 42d and the target variable blade opening map for surge noise, the supercharging deviation during normal operation and the surge noise for the surge noise limit Calculate the target variable blade opening. Further, the surge variable target variable blade opening degree calculation unit 42f calculates the intake air amount calculated by the intake air amount deviation calculation unit 43c described later when the engine 1 is in the post-processing operation based on the post-processing operation information. Based on the deviation, the surge noise limit, and the target variable blade opening map for surge noise during post-processing operation, the intake air amount deviation during post-processing operation and the target for surge noise at the surge noise limit Calculate the variable blade opening. Then, the calculation result is supplied to the variable blade opening degree control unit 42h.

  The surge abnormal noise generation determination unit 42g includes a supercharging deviation calculated by the supercharging deviation calculation unit 42e, an intention determination result determined by the driver intention determination unit 41c, and a surge abnormal noise limit calculation unit 42d. Based on the calculated surge noise limit, surge noise determination is performed. Specifically, if the intention determination result is deceleration, that is, the driver requests deceleration, the supercharging deviation is less than a predetermined value, and the surge noise limit is less than or equal to the predetermined value, there is a possibility of occurrence of surge noise. judge. Further, when neither the intention determination result nor the supercharging deviation applies, it is determined that there is no possibility of occurrence of surge abnormal noise. Then, the determination result is supplied to the variable blade opening degree control unit 42h.

  The variable blade opening control unit 42h is configured such that the target variable blade opening calculated by the target variable blade opening calculation unit 42b, the surge noise limit calculated by the surge noise limit calculation unit 42d, and the surge noise. Based on the target variable blade opening for surge abnormal noise calculated by the target variable blade opening calculating unit 42f and the determination result in the surge abnormal noise generation determining unit 42g. The operation of the actuator 13a is controlled so that the target variable blade opening for sound is obtained. In addition, when the target variable blade opening is larger than the target variable blade opening for surge abnormal noise, that is, the supercharging ratio at the target variable blade opening is higher than the supercharging ratio at the target variable blade opening for surge abnormal noise. When it becomes smaller, the operation of the actuator 13a is controlled so that the target variable blade opening degree is obtained. Then, the target variable blade opening or the target variable blade opening for surge noise is supplied to the exhaust gas recirculation valve control block 44 as the variable blade opening. Specifically, when the determination result in the driver intention determination unit 41c is determined that there is a possibility of occurrence of surge noise, and the surge noise limit is equal to or less than a predetermined value, the opening degree of the variable blades of the variable nozzle turbocharger 13 is The operation of the actuator 13a is controlled so that the target variable blade opening for surge noise is calculated so as to avoid noise due to surge. Then, the target variable blade opening for surge abnormal noise is supplied to the exhaust gas recirculation valve control block 44 as the variable blade opening. If it is determined that there is no possibility of occurrence of abnormal surge noise, or if the surge abnormal noise limit is larger than a predetermined value, the output performance and exhaust performance of the engine 1 are optimized for the opening degree of the variable blade of the variable nozzle turbocharger 13. The operation of the actuator 13a is controlled so that the target variable blade opening calculated in this way is obtained. Then, the target variable blade opening is supplied to the exhaust gas recirculation valve control block 44 as the variable blade opening. Also, when the target variable blade opening is larger than the target variable blade opening for surge abnormal noise, that is, the supercharging ratio at the target variable blade opening is higher than the supercharging ratio at the target variable blade opening for surge abnormal noise. When it becomes smaller, the operation of the actuator 13a is controlled so that the opening degree of the variable blade of the variable nozzle turbocharger 13 becomes the target variable blade opening degree. Then, the target variable blade opening is supplied to the exhaust gas recirculation valve control block 44 as the variable blade opening.

As shown in FIG. 5, the throttle valve control block 43 includes a target intake air amount calculation unit 43a, a target throttle opening calculation unit 43b, an intake air amount deviation calculation unit 43c, and a target throttle opening calculation for surge noise. 43d, surge abnormal sound generation determination unit 43e, and throttle opening control unit 43f.
The target intake air amount calculation unit 43a stores a target intake air amount map for calculating the target intake air amount from the target torque and the engine speed. Then, the target intake air amount calculation unit 43a is based on the target torque calculated by the target torque calculation unit 41a, the engine rotation speed detected by the crank angle sensor 7, and the target intake air amount map. A target intake air amount at the torque and the engine speed is calculated. Then, the calculation result is supplied to the target throttle opening calculation unit 43b and the intake air amount deviation calculation unit 43c.

The target throttle opening degree calculation unit 43b stores a target throttle opening degree map for calculating the target throttle opening degree from the fuel injection amount and the engine speed. The target throttle opening calculation unit 43b calculates the target intake air amount based on the actual intake air amount (mass flow rate) detected by the air flow sensor 19 when the engine 1 is in the post-processing operation based on the post-processing operation information. The target throttle opening is calculated so as to be the target intake air amount calculated by the unit 43a. That is, when the engine 1 is in the post-processing operation, the target throttle opening is feedback-controlled with the intake air amount. Further, the target throttle opening calculation unit 43b detects the fuel injection amount calculated by the fuel injection amount calculation unit 41d and the crank angle sensor 7 when the engine 1 is not in the post-processing operation based on the post-processing operation information. Based on the engine rotational speed and the target throttle opening map, the fuel injection amount and the target throttle opening at the engine rotational speed are calculated. Then, the target throttle opening calculation unit 43b is calculated target throttle opening degree as O ₂ concentration calculated at O ₂ concentration calculator 44a becomes a predetermined value exhaust performance is optimized for the engine 1 (corrected) To do. That is, feedback control of the target throttle opening is performed with the O ₂ concentration. Then, the calculation result is supplied to the throttle opening degree control unit 43f.

The intake air amount deviation calculation unit 43c subtracts the actual intake air amount (mass flow rate) detected by the air flow sensor 19 from the target intake air amount calculated by the target intake air amount calculation unit 43a, thereby obtaining the intake air amount. Calculate the deviation. Then, the calculation result is supplied to the surge abnormal noise target throttle opening calculation unit 43d and the surge abnormal noise occurrence determination unit 43e.
The target throttle opening calculation unit 43d for surge abnormal noise includes a surge that is a target opening of the electronically controlled throttle valve 15 that avoids abnormal noise due to a surge based on the intake air amount deviation and the surge abnormal limit during post-processing operation of the engine 1. A surge abnormal noise target throttle opening map for calculating the abnormal noise target throttle opening is stored. The surge abnormal noise target throttle opening map is set so that the surge abnormal noise target throttle opening increases, that is, the actual intake air amount increases as the surge abnormal noise limit decreases. Further, the surge abnormal noise target throttle opening map shows that the intake noise amount deviation is larger on the negative side, that is, as the actual intake air amount (mass flow rate) becomes larger than the target intake air amount, As the intake air amount deviation increases to the positive side, that is, as the target intake air amount becomes greater than the actual intake air amount (mass flow rate), the target throttle opening for surge noise is set to decrease. Yes. Then, the surge abnormal noise target throttle opening calculation unit 43d sets the fully opened position of the electronically controlled throttle valve 15 to the surge abnormal noise target throttle opening when the engine 1 is in normal operation based on the post-processing operation information. To do. Further, the surge abnormal noise target throttle opening calculation unit 43d, when the engine 1 is in the post-processing operation based on the post-processing operation information, the intake air amount deviation calculated by the intake air amount deviation calculation unit 43c, Based on the surge noise limit calculated by the surge noise limit calculation unit 42d and the target throttle opening map for surge noise, the intake air amount deviation during post-processing operation and the surge at the surge noise limit The target throttle opening for abnormal noise is calculated. Then, the setting result or calculation result is supplied to the throttle opening degree control unit 43f.

  The surge abnormal noise generation determination unit 43e determines the surge abnormal noise based on the intake air amount deviation calculated by the intake air amount deviation calculation unit 43c and the intention determination result determined by the driver intention determination unit 41c. I do. Specifically, if the intention determination result is deceleration, that is, the driver requests deceleration, and the intake air amount deviation is less than a predetermined value, it is determined that there is a possibility of occurrence of abnormal surge noise. Further, when neither the intention determination result nor the intake air amount deviation applies, it is determined that there is no possibility of occurrence of abnormal surge noise. Then, the determination result is supplied to the throttle opening degree control unit 43f.

  The throttle opening control unit 43f is a target throttle opening calculated by the target throttle opening calculation unit 43b and a target throttle opening for surge noise calculated by the target throttle opening calculation unit 43d for surge noise. The operation of the electronically controlled throttle valve 15 is controlled so as to reach the target throttle opening or the surge abnormal noise target throttle opening based on the determination result in the surge abnormal noise generation determination unit 43e. Specifically, if the surge noise occurrence determination unit 43e determines that there is a possibility of occurrence of a surge noise, the electronic control is performed so that the target throttle opening for surge noise is calculated so as to avoid the noise due to the surge. The operation of the control throttle valve 15 is controlled. When it is determined that there is no possibility of occurrence of abnormal surge noise, the operation of the electronically controlled throttle valve 15 is controlled so that the target throttle opening is calculated so that the output performance and exhaust performance of the engine 1 are optimized. .

As shown in FIG. 6, the exhaust gas recirculation valve control block 44 includes an O ₂ concentration calculation unit 44a, an intake air amount change rate calculation unit 44b, a target exhaust gas recirculation valve opening degree calculation unit 44c, and an exhaust gas recirculation amount calculation unit 44d. And a surge abnormal noise target exhaust gas recirculation valve opening calculation unit 44e, a surge abnormal noise occurrence determination unit 44f, and an exhaust gas recirculation valve opening control unit 44g.
The O ₂ concentration calculation unit 44 a is detected by the exhaust gas recirculation amount calculated by the exhaust gas recirculation amount calculation unit 44 d, the actual intake air amount (mass flow rate) detected by the air flow sensor 19, and the intake air temperature sensor 21. On the basis of the intake air temperature, the boost pressure detected by the boost sensor 20, and the fuel injection amount calculated by the fuel injection amount calculation unit 41d, the O ₂ concentration during operation of the engine 1 is calculated. Then, the calculation result is supplied to the target exhaust gas recirculation valve opening calculation unit 44c and the target throttle opening calculation unit 43b.

The intake air amount change rate calculation unit 44b is based on the actual intake air amount (mass flow rate) detected by the air flow sensor 19 and is the actual intake air amount that is the rate of change per hour of the actual intake air amount (mass flow rate). Calculate the rate of change. Then, the calculation result is supplied to the surge abnormal noise occurrence determination unit 44f.
The target exhaust gas recirculation valve opening degree calculation unit 44c stores a target exhaust gas recirculation valve opening degree map for calculating the target exhaust gas recirculation valve opening degree from the fuel injection amount and the engine speed. Then, the target exhaust gas recirculation valve opening calculation unit 44c includes the fuel injection amount calculated by the fuel injection amount calculation unit 41d, the engine speed detected by the crank angle sensor 7, and the target exhaust gas recirculation valve opening map. Based on the fuel injection amount and the target exhaust gas recirculation valve opening degree (corresponding to the basic exhaust gas recirculation valve opening degree of the present invention) at the engine speed. Further, the target EGR valve opening calculation section 44c sets the target EGR valve opening as O ₂ concentration calculated at O ₂ concentration calculator 44a becomes a predetermined value exhaust performance is optimized for the engine 1 to correct. That is, feedback control of the target exhaust gas recirculation valve opening degree is performed with the O ₂ concentration. Then, the calculation result is supplied to the surge abnormal noise target exhaust gas recirculation valve opening calculation unit 44e and the exhaust gas recirculation valve opening control unit 44g.

The exhaust gas recirculation amount calculation unit 44d is detected by the fuel injection amount calculated by the fuel injection amount calculation unit 41d, the actual intake air amount (mass flow rate) detected by the airflow sensor 19, and the intake air temperature sensor 21. The exhaust gas recirculation amount is calculated based on the intake air temperature, the atmospheric pressure detected by the atmospheric pressure sensor 34, and the outside air temperature detected by the outside air temperature sensor 35. Then, the change calculation result is supplied to the surge abnormal noise occurrence determination unit 44f and the O ₂ concentration calculation unit 44a.

  The surge abnormal noise target exhaust gas recirculation valve opening calculation unit 44e includes a first additional coefficient map for calculating the first additional coefficient from the surge abnormal noise limit, and a second additional coefficient based on the variable blade opening and the supercharging deviation. The second additional coefficient map for calculating is stored. The first additional coefficient map is set so that the first additional coefficient becomes smaller as the surge abnormal noise limit becomes smaller. The second additional coefficient map is set so that the second additional coefficient decreases as the variable blade opening degree and the supercharging deviation decrease. Based on the surge noise limit calculated by the surge noise limit calculation unit 42d and the first additional coefficient map, the target exhaust gas recirculation valve opening calculation unit 44e for surge noise has a first value at the surge noise limit. Calculate the additional coefficient. Further, the surge abnormal noise target exhaust gas recirculation valve opening calculating unit 44e includes a variable blade opening supplied from the variable blade opening control unit 42h, a supercharging deviation supplied from the supercharging deviation calculating unit 42e, Based on the 2 additional coefficient map, the variable blade opening and the second additional coefficient in the supercharging deviation are calculated. Then, the surge abnormal noise target exhaust gas recirculation valve opening calculation unit 44e sets the first additional coefficient and the second additional coefficient to the target exhaust gas recirculation valve opening previously calculated by the target exhaust gas recirculation valve opening calculation unit 44c. Multiply to calculate the target exhaust gas recirculation valve opening for surge noise. That is, the target exhaust gas recirculation valve opening for surge abnormal noise is the target previously calculated by the target exhaust gas recirculation valve opening calculation unit 44c as the surge abnormal noise limit, variable blade opening, or supercharging deviation decreases. The opening is smaller than the exhaust recirculation valve opening. Then, the calculation result is supplied to the exhaust gas recirculation valve opening degree control unit 44g.

  The surge abnormal noise occurrence determination unit 44f calculates the actual intake air amount (mass flow rate) detected by the air flow sensor 19, the variable blade opening degree supplied from the variable blade opening control unit 42h, and the intake air amount change rate calculation. The rate of change in the intake air amount calculated by the unit 44b, the target exhaust gas recirculation valve opening calculated by the target exhaust gas recirculation valve opening calculation unit 44c, and the exhaust gas recirculation amount calculated by the exhaust gas recirculation amount calculation unit 44d And surge abnormal noise determination is performed based on the intention determination result determined by the driver intention determination unit 41c. Specifically, the intention determination result determined by the driver intention determination unit 41c is acceleration, that is, the driver requests acceleration, the variable blade opening is smaller than a predetermined value, and the actual intake air amount (mass flow rate) is More than the predetermined value, the intake air amount change rate is larger than the predetermined value, the intake air amount rapidly decreases, and the target exhaust gas recirculation valve opening degree is larger than the minimum limit opening degree that is the minimum opening degree that the exhaust gas recirculation valve 31 can operate. If the exhaust gas recirculation amount is larger than a predetermined value, it is determined that there is a possibility of occurrence of surge abnormal noise. Further, if any one of the intention determination result, the actual intake air amount (mass flow rate), the intake air amount change rate, and the variable blade opening degree does not apply, it is determined that there is no possibility of occurrence of surge noise. Then, the determination result is supplied to the exhaust gas recirculation valve opening degree control unit 44g. The variable blade opening is used to estimate the exhaust pressure. For example, if an exhaust pressure sensor is provided, the exhaust pressure may be used instead of using the variable blade opening.

  The exhaust gas recirculation valve opening degree control unit 44g is calculated by the target exhaust gas recirculation valve opening degree calculation unit 44c and the target exhaust gas recirculation valve opening degree calculation unit 44e. Based on the target exhaust gas recirculation valve opening degree for surge abnormal noise and the determination result in the surge abnormal noise occurrence determination unit 44f, the opening degree of the exhaust gas recirculation valve 31 is the target exhaust gas recirculation valve opening degree or the target exhaust gas for surge abnormal noise. The operation of the exhaust gas recirculation valve 31 is controlled so that the recirculation valve opening degree is reached. Specifically, it is determined that there is a possibility of occurrence of surge noise, and the target exhaust gas recirculation valve opening for surge noise is the minimum opening of the exhaust gas recirculation valve 31 that can suppress surge noise. If the target exhaust gas recirculation valve opening for surge abnormal noise is larger than the target exhaust gas opening degree and the target exhaust gas recirculation valve opening degree is larger than the target exhaust gas recirculation valve opening degree, the target for surge abnormal noise calculated so as to avoid abnormal noise due to surge is calculated. The operation of the exhaust gas recirculation valve 31 is controlled so that the exhaust gas recirculation valve opening degree is reached. In addition, it is determined that there is no possibility of occurrence of abnormal surge noise, or the target exhaust gas recirculation valve opening for surge abnormal noise is less than the noise suppression minimum opening, or the target exhaust gas recirculation valve opening for surge abnormal noise is the target exhaust gas recirculation valve If the opening is equal to or less than the opening, the operation of the exhaust gas recirculation valve 31 is controlled so that the opening degree of the exhaust gas recirculation valve 31 becomes the target exhaust gas recirculation valve opening degree calculated so that the output performance and exhaust performance of the engine 1 are optimized. To do.

  When there is a possibility that abnormal noise due to a surge may occur when the vehicle decelerates, the electronic control unit 40 has a variable blade opening degree of the variable nozzle turbocharger 13 that suppresses the occurrence of abnormal noise due to the surge. The variable nozzle turbocharger control for controlling the operation of the actuator 13a and the throttle valve control for controlling the operation of the electronic control throttle valve 15 so that the throttle opening of the electronic control throttle valve 15 suppresses the generation of abnormal noise due to surge. Do at least one of the following.

Next, variable nozzle turbocharger control and throttle valve control in the electronic control unit 40 will be described.
FIG. 7 is a flowchart of variable nozzle turbocharger control. FIG. 8 is a flowchart of throttle valve control.
First, variable nozzle turbocharger control will be described.

In step S10, the driver's intention determination unit 41c determines whether the driver requests acceleration or deceleration. Then, the process proceeds to step S12.
In step S12, the surge abnormal noise occurrence determination unit 42g determines whether or not the vehicle is decelerating. Specifically, the driver intention determination unit 41c determines that the driver is requesting deceleration, and determines whether or not the vehicle is in a deceleration state. If the determination result is true (Yes) and the driver intention determination unit 41c determines that the driver is requesting deceleration, and the vehicle is in a deceleration state, the process proceeds to step S14. If the determination result is NO (No), the driver intention determination unit 41c determines that the driver does not request deceleration, and if the vehicle is not in a deceleration state, the process proceeds to step S32.

In step S14, it is determined whether or not the engine 1 is in a post-processing operation. Specifically, it is determined whether or not the engine 1 is in the post-processing operation based on the post-processing operation information. If the determination result is true (Yes) and the engine 1 is in the post-processing operation, the process proceeds to step S16. If the determination result is NO (No) and the engine 1 is not in the post-processing operation, the process proceeds to step S24.
In step S16, the intake air amount deviation calculation unit 43c calculates the intake air amount deviation. Then, the process proceeds to step S18.

In step S18, the surge abnormal noise occurrence determination unit 42g determines whether or not there is a possibility of occurrence of surge abnormal noise. If the determination result is true (Yes) and there is a possibility of occurrence of surge noise, the process proceeds to step S20. If the determination result is no (No) and there is no possibility of occurrence of surge noise, the process proceeds to step S22.
In step S20, the surge variable target variable blade opening calculator 42f calculates the surge variable target variable blade opening. Specifically, the intake air amount deviation calculated by the intake air amount deviation calculation unit 43c, the surge noise limit calculated by the surge noise limit calculation unit 42d, and the target variable blade for surge noise during post-processing operation Based on the opening map, the intake air amount deviation during post-processing operation and the surge variable target variable blade opening at the surge noise limit are calculated. Then, the variable blade opening control unit 42h controls the operation of the actuator 13a so that the opening of the variable blade of the variable nozzle turbocharger 13 becomes the target variable blade opening for surge noise. Then, this routine is returned.

  On the other hand, in step S22, the target variable blade opening degree calculation unit 42b calculates the target variable blade opening degree. Specifically, based on the target torque, the engine rotational speed, and the target variable blade opening map during post-processing operation, the target torque during post-processing operation and the target variable blade opening at the engine rotational speed are calculated. Then, the variable blade opening degree control unit 42h controls the operation of the actuator 13a so that the variable blade opening degree of the variable nozzle turbocharger 13 becomes the target variable blade opening degree. Then, this routine is returned.

In step S24, a supercharging state is calculated. Specifically, the target supercharging pressure calculation unit 42a calculates the target supercharging pressure, and the supercharging deviation calculation unit 42e calculates the supercharging deviation. Then, the process proceeds to step S26.
In step S26, the surge abnormal noise occurrence determination unit 42g determines whether or not there is a possibility of occurrence of surge abnormal noise. If the determination result is true (Yes) and there is a possibility of occurrence of surge noise, the process proceeds to step S28. If the determination result is negative (No) and there is no possibility of occurrence of surge noise, the process proceeds to step S30.

  In step S28, the target variable blade opening for surge abnormal noise calculation unit 42f calculates the target variable blade opening for surge abnormal noise. Specifically, based on the supercharging deviation calculated by the supercharging deviation calculating unit 42e, the surge abnormal limit calculated by the surge abnormal limit calculating unit 42d, and the target variable blade opening map for surge abnormal noise. Thus, the supercharging deviation during normal operation and the target variable blade opening for surge noise at the surge noise limit are calculated. Then, the variable blade opening control unit 42h controls the operation of the actuator 13a so that the opening of the variable blade of the variable nozzle turbocharger 13 becomes the target variable blade opening for surge noise. Then, this routine is returned.

  On the other hand, in step S30, the target variable blade opening degree calculation unit 42b calculates the target variable blade opening degree. Specifically, based on the target torque, the engine rotational speed, and the target variable blade opening map, the target torque during normal operation and the target variable blade opening at the engine rotational speed are calculated. Then, the variable blade opening degree control unit 42h controls the operation of the actuator 13a so that the variable blade opening degree of the variable nozzle turbocharger 13 becomes the target variable blade opening degree. Then, this routine is returned.

  In step S32, it is determined whether or not the engine 1 is in a post-processing operation. Specifically, it is determined whether or not the engine 1 is in the post-processing operation based on the post-processing operation information. If the determination result is true (Yes) and the engine 1 is in the post-processing operation, the process returns to step S22. If the determination result is no (No) and the engine 1 is not in the post-processing operation, the process returns to step S30.

Next, throttle valve control will be described.
In step S110, the driver's intention determination unit 41c determines whether the driver requests acceleration or deceleration. Then, the process proceeds to step S112.
In step S112, the surge abnormal noise occurrence determination unit 43e determines whether or not the vehicle is in a decelerating state. Specifically, the driver intention determination unit 41c determines that the driver is requesting deceleration, and determines whether or not the vehicle is in a deceleration state. If the determination result is true (Yes) and the driver intention determination unit 41c determines that the driver is requesting deceleration, and the vehicle is in a deceleration state, the process proceeds to step S114. If the determination result is no (No), the driver intention determination unit 41c determines that the driver does not request deceleration, and if the vehicle is not in a deceleration state, the process proceeds to step S132.

  In step S114, it is determined whether or not the engine 1 is in a post-processing operation. Specifically, it is determined whether or not the engine 1 is in the post-processing operation based on the post-processing operation information. If the determination result is true (Yes) and the engine 1 is in the post-processing operation, the process proceeds to step S116. If the determination result is no (No) and the engine 1 is not in the post-processing operation, the process proceeds to step S124.

In step S116, the intake air amount deviation calculation unit 43c calculates the intake air amount deviation. Then, the process proceeds to step S118.
In step S118, the surge abnormal noise occurrence determination unit 43e determines whether or not there is a possibility of occurrence of surge abnormal noise. If the determination result is true (Yes) and there is a possibility of occurrence of abnormal surge noise, the process proceeds to step S120. If the determination result is no (No) and there is no possibility of occurrence of abnormal surge noise, the process proceeds to step S122.

  In step S120, the surge abnormal noise target throttle opening calculator 43d calculates the surge abnormal noise target throttle opening. Specifically, the intake air amount deviation calculated by the intake air amount deviation calculation unit 43c, the surge noise limit calculated by the surge noise limit calculation unit 42d, and the surge noise limit become smaller. As the target throttle opening for sound increases, the actual intake air amount increases, and the intake air amount deviation increases to the negative side, that is, the actual intake air amount (mass flow rate) becomes larger than the target intake air amount, The target throttle opening for surge noise becomes smaller as the target throttle opening becomes larger and the intake air amount deviation becomes larger on the positive side, that is, the target intake air amount becomes larger than the actual intake air amount (mass flow rate). Surge noise target slot at the intake air amount deviation and the surge noise limit during post-processing operation based on the surge noise target throttle opening map set as follows To calculate the degree of opening. Then, the throttle opening control unit 43f controls the operation of the electronic control throttle valve 15 so that the opening degree of the electronic control throttle valve 15 becomes the surge abnormal noise target throttle opening degree. Then, this routine is returned.

  On the other hand, in step S122, the target throttle opening calculation unit 43b calculates the target throttle opening. Specifically, the target throttle opening is calculated so that the actual intake air amount (mass flow rate) detected by the air flow sensor 19 becomes the target intake air amount calculated by the target intake air amount calculation unit 43a. Then, the throttle opening control unit 43f controls the operation of the electronic control throttle valve 15 so that the opening degree of the electronic control throttle valve 15 becomes the target throttle opening degree. Then, this routine is returned.

In step S124, the supercharging state is calculated. Specifically, the target supercharging pressure calculation unit 42a calculates the target supercharging pressure, and the supercharging deviation calculation unit 42e calculates the supercharging deviation. Then, the process proceeds to step S126.
In step S126, the surge abnormal noise occurrence determination unit 43e determines whether or not there is a possibility of occurrence of surge abnormal noise. If the determination result is true (Yes) and there is a possibility of occurrence of surge noise, the process proceeds to step S128. If the determination result is negative (No) and there is no possibility of occurrence of abnormal surge noise, the process proceeds to step S130.

  In step S128, the surge variable target throttle opening calculator 43d calculates the surge variable target variable blade opening. Specifically, the fully opened position of the electronically controlled throttle valve 15 is set to the target throttle opening for surge noise. Then, the throttle opening control unit 43f controls the operation of the electronic control throttle valve 15 so that the opening degree of the electronic control throttle valve 15 becomes the surge abnormal noise target throttle opening degree. Then, this routine is returned.

On the other hand, in step S130, the target throttle opening calculation unit 43b calculates the target throttle opening. For details, O ₂ concentration calculated at O ₂ concentration calculator 44a calculates the target throttle opening degree to a predetermined value which exhaust performance is optimized for the engine 1. Then, the throttle opening control unit 43f controls the operation of the electronic control throttle valve 15 so that the opening degree of the electronic control throttle valve 15 becomes the target throttle opening degree. Then, this routine is returned.

  In step S132, it is determined whether or not the engine 1 is in a post-processing operation. Specifically, it is determined whether or not the engine 1 is in the post-processing operation based on the post-processing operation information. If the determination result is true (Yes) and the engine 1 is in the post-processing operation, the process returns to step S122. If the determination result is no (No) and the engine 1 is not in the post-processing operation, the process returns to step S130.

Thus, in the control device for an internal combustion engine of the present invention, it is determined that the vehicle is decelerating and in the post-processing operation, the intake air amount deviation is less than a predetermined value, the surge noise limit is less than the predetermined value, If it is determined that there is a possibility of occurrence of abnormal surge noise, the target throttle opening for surge abnormal noise increases and the actual intake as the deviation of intake air amount, surge abnormal noise limit, and surge abnormal noise limit decrease. As the air volume increases and the intake air volume deviation increases to the negative side, the surge abnormal noise target throttle opening increases, and as the intake air volume deviation increases to the positive side, the surge abnormal noise target throttle opens. Based on the target throttle opening map for surge noise that is set to be smaller, the target throttle opening for surge noise at the intake air amount deviation and the surge noise limit during post-processing operation is reduced. Is calculated, to control the operation of the electronic control throttle valve 15 so that the opening of the electronic controlled throttle valve 15 becomes the target throttle opening surge abnormal noise. Or, if it is determined that the vehicle is in a post-processing operation in a deceleration state and there is no risk of occurrence of abnormal surge noise, or if the vehicle is not in a deceleration state and is in a post-processing operation, the actual intake air The target throttle opening is calculated so that the amount (mass flow rate) becomes the target intake air amount, and the operation of the electronic control throttle valve 15 is controlled so that the opening of the electronic control throttle valve 15 becomes the target throttle opening. Alternatively, it is determined that the vehicle is decelerating and not in a post-processing operation, the intake air amount deviation is less than a predetermined value, the surge noise limit is less than the predetermined value, and it is determined that there is a possibility of occurrence of surge noise. If the electronic control throttle valve 15 is fully opened, the surge abnormal noise target throttle opening is set, and the electronic control throttle valve 15 opens to the surge abnormal noise target throttle opening. The operation of the valve 15 is controlled. Or the vehicle is in a deceleration state, is determined not to be in the post-processing operation, when it is determined yet with no risk of surge noises generated, O ₂ concentration engine 1 calculated by the O ₂ concentration calculator 44a The target throttle opening is calculated so that the exhaust performance of the engine becomes a predetermined value, and the operation of the electronic control throttle valve 15 is controlled so that the opening of the electronic control throttle valve 15 becomes the target throttle opening. .

  Therefore, the opening degree of the electronically controlled throttle valve 15 increases as the surge noise limit decreases during post-processing operations such as sulfur desorption processing of the NOx storage reduction catalyst 26 and regeneration processing of the diesel particulate filter 25. By controlling the opening degree of the electronically controlled throttle valve 15, the intake air amount can be increased and the occurrence of a surge can be avoided when the intake air amount decreases and there is no room for surge. Therefore, the generation of surge noise can be suppressed.

  Further, the intake air amount deviation becomes larger on the positive side so that the opening degree does not become too small as the actual intake air amount becomes larger than the target intake air amount. That is, as the actual intake air amount becomes smaller than the target intake air amount, the opening degree of the electronic control throttle valve 15 is controlled so that the opening degree of the electronic control throttle valve 15 does not become too large. By setting the optimum intake air amount, the temperature drop of the exhaust gas introduced into the diesel particulate filter 25 or the NOx occlusion reduction catalyst 26 and the increase in oxygen concentration in the exhaust gas are suppressed, and the regeneration failure due to the temperature drop of the diesel particulate filter 25 is suppressed. In addition, it is possible to prevent an excessive increase in temperature of the oxidation catalyst 24 and the NOx storage reduction catalyst 26 due to excessive oxygen supply amount.

  Further, during post-processing operation, the target variable blade opening for surge noise is calculated so that the opening of the variable blade of the variable nozzle turbocharger 13 increases, that is, the supercharging ratio decreases, as the surge noise limit decreases. In addition, the opening degree of the variable blades of the variable nozzle turbocharger 13 is controlled so as to be the target variable blade opening degree for surge abnormal noise, and the exhaust pressure upstream of the turbine is reduced to reduce the actual supercharging pressure. Thus, the occurrence of surge can be avoided and the occurrence of surge noise can be suppressed.

1 engine (internal combustion engine)
13 Variable nozzle turbocharger (Flow path variable supercharging means)
13a Actuator (Supercharging ratio variable means)
15 Electronically controlled throttle valve (intake air volume adjustment means)
16 Intake manifold (intake passage)
17 Intake pipe (intake passage)
19 Air flow sensor (actual intake air amount detection means)
20 Boost sensor (actual boost pressure detection means)
22 Exhaust manifold (exhaust passage)
23 Exhaust pipe (exhaust passage)
24 Oxidation catalyst (exhaust gas purification means)
25 Diesel particulate filter (exhaust gas purification means)
26 NOx storage reduction catalyst (exhaust gas purification means)
40 Electronic control unit (margin calculation means, intake air amount control means, supercharging ratio control means, target boost pressure setting means, target intake air amount setting means, first target opening setting means, second target opening setting means)

Claims (5)

A turbine provided in an exhaust passage of an internal combustion engine mounted on a vehicle and having a supercharging ratio varying means for varying a supercharging ratio by varying an exhaust passage area; and an intake passage of the internal combustion engine provided by the turbine A variable flow path supercharging means including a driven compressor;
An actual intake air amount detection means for detecting the actual intake air amount;
Target intake air amount setting means for setting a target intake air amount based on the operating state of the internal combustion engine;
An intake air amount adjusting means disposed in the intake passage for adjusting the actual intake air amount;
An exhaust purification means downstream of the exhaust passage in the exhaust flow direction of the flow path variable supercharging means;
A margin calculation for calculating a margin to the limit supercharging ratio in an operating state of the internal combustion engine, in which a limit supercharging ratio at which a surge noise is generated in the compressor is preset according to the intake air amount of the internal combustion engine Means,
The amount of intake air that controls the degree of opening of the intake air amount adjusting means in accordance with the deviation between the actual intake air amount and the target intake air amount and the margin during the exhaust purification capacity recovery operation of the exhaust purification means And a control means for controlling the internal combustion engine.   2. The internal combustion engine according to claim 1, wherein the intake air amount control unit controls the opening degree of the intake air amount adjusting unit so that the opening degree increases as the margin decreases. 3. Control device. First target opening setting means for setting a target opening of the intake air amount adjusting means so as to be the target intake air amount set by the target intake air amount setting means;
The target opening is set larger as the actual intake air amount becomes larger than the target intake air amount, and the target opening is set smaller as the target intake air amount becomes larger than the actual intake air amount. 2 target opening setting means,
The intake air amount control means sets the target opening set by the first and second target opening setting means at least when the vehicle is in a decelerating state and during the exhaust purification capacity recovery operation. The control device for an internal combustion engine according to claim 1 or 2, wherein the opening degree of the intake air amount adjusting means is controlled based on the opening degree.   During the exhaust purification capacity recovery operation of the exhaust purification means, the supercharging for controlling the opening degree of the supercharging ratio variable means according to the deviation between the actual intake air amount and the target intake air amount and the margin The control device for an internal combustion engine according to any one of claims 1 to 3, further comprising a ratio control means.   5. The internal combustion engine according to claim 4, wherein the supercharging ratio control means controls the opening degree of the supercharging ratio variable means so that the supercharging ratio becomes smaller as the margin becomes smaller. Engine control device.

Images